public static T FirstOrDefault <T>(Expression <Func <T, bool> > expression) where T : class
{
var visit = new MyExpressionVisitor();
visit.Visit(expression);
var sqlWhere = visit.WhereMarkUp <T>();
var tableAttr = GetTableAttribute <T>();
var sql = SqlReplaceWhiteSpace($"Select Top 1 * from {tableAttr.TableName}{ sqlWhere} ;");
IList <T> result = GetFillDataSet <T>(sql);
return(result.FirstOrDefault());
}
public static bool Update <T>(Expression <Func <T, bool> > expression, dynamic updateObj) where T : class
{
var visit = new MyExpressionVisitor();
visit.Visit(expression);
var sqlWhere = visit.WhereMarkUp <T>();
var tableAttr = GetTableAttribute <T>();
var setParam = GetSetParam(updateObj);
var sql = SqlReplaceWhiteSpace($"Update {tableAttr.TableName} Set {setParam}{ sqlWhere} ;");
var res = DBHelper.ExecuteNonQuery(sql);
return(res > 0 ? true : false);
}
public static int Count <T>(Expression <Func <T, bool> > expression)
{
var visit = new MyExpressionVisitor();
visit.Visit(expression);
var sqlWhere = visit.WhereMarkUp <T>();
var tableAttr = GetTableAttribute <T>();
var sql = SqlReplaceWhiteSpace($"Select Count(*) from {tableAttr.TableName}{ sqlWhere} ;");
var result = DBHelper.ExecuteScalar(sql);
var count = Convert.ToInt32(result);
return(count);
}
